This is from the Newcastle Chronicle of August 1766. Fraud is not a new crime, clearly, but this pair seem to have been at it for some time.

Yesterday two Jews were taken into custody in Dukes-place for going about this city, pretending to be constables and taking people into custody into order to extort money from them – they were likewise charged with attending at fires, under the pretence of protecting the unhappy sufferers from being robbed, and behaving improperly themselves.